In the production, packaging and distribution of articles, various conveyance systems are used to transport those articles from one location to another. Combinations of various conveyance modules are used to move the articles to a desired location, preferably without damage to the article being conveyed. The use of air as a method or an aid to conveyance is well known and common.
For example, in the case of conveyance of stacks of newspapers, air conveyance tables are used where a change of direction is required and to bridge the gaps between conveyors. Often such tables are used to support the item while the direction of travel of the item is changed by some mechanical means. Such an air support allows for the change of direction without damaging the bottom surface of the traveling item. Examples of such devices can be found in U.S. Pat. No. 3,469,887 and European Patent Office Publication EP 0761545.
In known methods, change in lanes of travel or change in direction usually requires the use of impinging air on the side of the article or a pneumatic or mechanical means to push the article from one direction into another direction or position. Such means can damage the item and introduces more moving parts to a conveyance system. Additional moving parts means there are more things that require maintenance or that can malfunction.
In systems where articles are produced at a rate faster than they can be handled by subsequent processes (e.g., subsequent packaging or manufacturing systems), the stream of articles is often split between multiple subsequent process streams. For example, where multiple, end-packaging machines are used, an article stream may be regularly alternated between each of the packaging streams. Such a process provides alternating periods where a glut of articles is provided to a particular packaging machine (i.e., articles are provided at a rate greater than the packaging machine can handle) followed by a starvation period when no articles are provided to that packaging machine. In the periods of glut, the packaging machine works at its peak rate while articles wait in a queue to be packaged. In the periods of starvation, the machine sits idle as it awaits its next glut of articles. During the starvation period of one machine, another machine is normally in a glut period.
While a system using multiple sets of machines can handle more articles in a single period than a single machine could handle on its own, there are problems with such a system. First, by cycling between periods of starvation and glut, the machines are forced to operate in a cycle alternating between maximum output and sitting idle. This is not the optimum operating condition for any machine; constant starting and stopping of the machine will cause undue wear on the machine and result in a shorter time between repairs and increased repair downtime. The most efficient use of such a multiple machine system is achieved with a regular, continuous supply of articles to all machines.
Secondly, such a system requires a means for diverting flow of articles between the multiple machines. One such prior art set-up is shown in FIG. 1. In the system of FIG. 1, articles 12 produced by the manufacturing equipment are conveyed on an input conveyor 11 to the diverting equipment 14. The diverting equipment 14 comprises a set of mechanical arms between which the articles 12 pass to either of two conveyors 17,19, depending upon the arrangement of the diverting equipment 14. When it is desired to switch from one conveyor to the other conveyor, the mechanical arms close upon the articles 12 passing between the arms, thus trapping the articles 12 between the arms. Simultaneously, the set of mechanical arms pivots with the trapped articles over to the second conveyor 19. When positioned over the second conveyor 19, the mechanical arms spread and release the articles 12 that have accumulated within the closed mechanical arms.
A problem with such a set up is that articles accumulate behind the articles trapped within the mechanical arms until the mechanical arms release the articles. If the arms cycle slower than the manufacturing equipment is producing the articles, there is a danger that the articles could accumulate back into, and jam, the manufacturing equipment. Another problem is that articles can become jammed within the arms of the diverting equipment 14 if the articles are not properly detected and/or the actuation of the arms is not properly timed. Additionally, such mechanical arms have the disadvantage of pinching the items that are caught at the outlet of the mechanical arms. Such pinching can damage the article and such damaged articles may cause problems in subsequent packaging processes. Finally, there will be a gap in articles being sent to any of the multiple, subsequent processes while the article flow is being switched from one conveyor to another. As discussed above, this will result in less than optimal machine-use.
In view of the issues above, it is desired to have a means of conveyance capable of separating one or more article streams into two or more output streams without the impacting or pinching the side of the articles within the article stream. It is further desired that system require a minimum of energy to move the articles within the article stream.